The present invention relates to a disk drive and an arm/coil support assembly. Particularly, the present invention is concerned with a disk drive suitable for a hard disk drive having a single disk for recording user data thereon, as well as an arm coil support assembly mounted thereon.
Devices using various types of media such as optical disks and magnetic tapes are known as information recording and reproducing devices. Among them, hard disk drives (HDDs) have become popular as storage devices for computers to such an extent that they are one of the storage devices indispensable for today's computers. Further, not limited to computers, their application is widening more and more due to the superior characteristics with the advent of moving picture recording/reproducing devices, car navigation systems, removable memories for digital cameras and so on.
The HDD includes a magnetic disk for recording data and a head for writing and reading data between it and the magnetic disk. The head includes a head element as a thin film element and a slider with the head element disposed on a surface thereof. The head element includes a write element which converts an electric signal into a magnetic field in accordance with data to be recorded onto the magnetic disk and a read element which converts a magnetic field provided from the magnetic disk into an electric signal. Typically, both write element and read element are integrally formed in one thin film element.
The HDD further includes an actuator for moving the head to a desired position over the magnetic disk. The actuator is driven by a voice coil motor (VCM) and moves pivotally about a pivot shaft, thereby moving the head radially over the magnetic disk which is rotating. As a result, the head (head element) makes access to a desired track formed on the magnetic disk, whereby read and write of data can be performed.
The HDD includes a head stack assembly (HSA) adapted to rotate up to a predetermined position over the disk while holding the head. The head stack assembly includes a VCM coil, a head gimbals assembly (HGA), a bearing unit and a flexible printed circuit (FPC) board, the head gimbals assembly comprising a gimbals which holds the head, a suspension and an arm.
The FPC board is a circuit board for the transfer of signals provided from the head and a driving current for the VCM coil. A pre-amplifier for amplifying signals handled in the head element is mounted on the FPC board.
The HDD includes a trace for transmitting signals from the head to FPC or from FPC to the head. The trace is a wiring portion extending from the head to terminals formed on the FPC board. One end of the trace is connected to the head and an opposite end thereof is connected to the FPC board. The trace is also called ILS (Integrated Leads Suspension) or FOS (Flex On Suspension).
For example, in Japanese Patent Laid-open No. Hei 9-321010 (Patent Document 1) is disclosed a magnetic disk drive wherein a trace connecting between a head and FPC is disposed using as guide a stepped or grooved portion of an arm. An actuator portion used in the magnetic disk drive described in the publication includes plural gimbals which support magnetic head sliders elastically, plural guide arms (arms) having rigidity and supporting the gimbals, an actuator (carriage (a coil support for supporting a VCM coil) and VCM) which holds the arms through a clamp member and on a side face of which are provided FPC terminals connected to the exterior, and plural printed wiring patterns (traces) formed on side faces of the arms and on planar portions of the gimbals parallel to a magnetic disk.
The arms are each provided on a side edge thereof with a stepped portion of a laterally convex shape, and traces are affixed to upper and lower surfaces of the stepped portion to effect wiring. This is because the spacing between magnetic disks tends to become narrower to meet the recent demand for the reduction in size and thickness of a magnetic disk drive and so it is difficult to lay cables on the arm surface and also because the use of the stepped portion as guide intends to facilitate wiring.